Electric furnace



1,614,321 Janl1 1927' E. L. sMALLEY Il HMI 4 14mm l 1 'i H/ /ww my Patented Jan. 11, 1927.

UNITED STATES PATENT OFFICE.

EDWDI L. SHALLEY, 0F SOUTH ORANGE, NEW JERSEY, ASSIGNOB TO ELECTRIC HEAT- ING APPARATUS COMPANY,

marmo palmen mea :une 1,

My invention relates to improvements in electric furnaces and the same has for its object more particularly to provide an efficient and reliable furnace in which the heating elements thereof may be readily inserted and removed.

Further said invention has for its object to rovide a furnace in which the inner sur ace of the wall thereof is extended to provide a. surface of increased heat radiating area for directing the heat rays towards the interior space of the furnace.

Further said invention has for its object to provide a furnace in which the heating elements are removabl mounted on the wall thereof in exposed re ations to the interior space of the furnace.

Other features and advantages of my invention will hereinafter appear.

In the drawings Figure 1 is a partial, vertical section of a furnace" or heater embodying my inventive features.

Fig. 2 is an enlarged section on the line 2-2 of Fig. 1.

Fig. 3 is a similarly enlarged section on the line 3--3 of Fig. 1.

Fig. 4 is a partial side sectional view of amodified form of furnace wall having resistor retainin means, and

Fig. 5 is a nt view of Fig. 4.

In Fig. 1 I have shown a portion of a furnace including an end walll, a side wall 2, and its top 3, all composed of suitable material, such as fire brick.

The inner surface of the walls of the furnace are rovided with recesses or channels 4'formedy the projections or ribs 5, there-4 .by providing an extended surface of a corrugated or undulatory character and of increased heat radiating area.

When it is appreciated that part of the effective heat employed in the furnace is obtained by reflection from its walls it will be apparent that gain in tem erature is a function of the increased sur ace area which is provided in the manner indicated. The refcesses 4 are preferably employed to receive the several portions or strands 6 of resistor elements of a preformed return-bend type, which are retained or supported in operative position therein in close proximity to the wall in the flanged retaining members 8, shown as of rail shape and extend-ing under the bends 7. The members 8 are of refracf taining or NEWARK, NEW maaar. minimos.

1982. Serial No. 565,287.

tory material Iand permit, by reason of the non-conductive character thereof, direct en- `gagement of the flanges thereof with the resistor element at the bends 7. The members 8 are slidabl mounted in and retained by flanges -9 in t e grooves 10 provided in the brick constituting the furnace Wall.

It will be noted that the rail heads extend beyond the wall inner` surface sufiiciently to `rpermit them to engageithe end bends of the resistor elements to thereby retain said resistors in their effective posim tion against the furnace walls-- The construction illustrated in Figs. 1 to 3 permits of the removal of the heating ele ments by removin the members 8 from their grooves 10. n Figs. 4 and 5 the remembers are illustrated as fixed and com rise flanges 11 'directed inwardly to wa s each other, said flan s being supported in spaced relation to t e wall by connecting'members or webs 12. The members 11 and 12 form betweenA the same recess to receive the resistor element which is inserted into position through an opening located between the flanges 11. The several portions or strands 6 of the'resistor element are located, as in Figs. 1 to 3, in recesses on the wall and are maintained in spaced relation by the projections or ribs 14 car ried by the wall and between-which said recesses are formed. The heating element is retained in operative position in close proximity to the wall by the flanges 11, which are of unequal width, roviding a deeper channel at one end of, the recess formed by members 11 and 12 than at the op site end. The resistor element is of less width than that of the recess in which it is located and of a width greater than the o ning between said flanges 11, whereby t e same may be inserted into and removed from position through said openin and retained in position by flanges 11 a apted .to engage the bends 7 thereof.-

In my invention the inner surfaces of the wall of the furnace are enlarged to provide extended or increased heat radiating areas, and on which the resistor elements are mounted in the several recesses 4 or 13 thereof,the projections 5 or 14 serving as mea-ns to maintain the several strands of the resistor element in spaced relation. Each of the several recesses 4 or 13 has outwardly1 diverging wall portions 15 at thebase o which a portion of a resistor element lies in exposed relation to the interior space of the furnace, the several recesses 4 or 13 forming a plurality of rejectors each individual to the portion of the resistor element therein for directing the heat rays emitted thereby efficiently towards the interior space of the furnace, either directly from said element or by reflection or emission from the Walls 15 of said recesses and from the convex intermediate projection separating said recesses from each other.

The efficiency attained with my improved furnace results from its larger wall surface area for heat exchange, and the particular relation established between the resistor and the novel, undulatory form of the wall surface, whereby a liberal proportion of heat from the resistor, which ordinarily would be merely absorbed by the furnace Wall. serves effectively as reflected heat to raise the furnace temperature.

The arrows in Fig. 2 indicate approximately the lines of radiant heat as emanating from the resistor and reflected toward the furnace interior from the walls 15 of the undulations.

In the instance of a furnace composed of fire brick these may be provided with registering means, such as indicated at 16 in Fig. 4, in order that .the relative location of the brick may permit proper alignment of the undulations thereo and the disposition of the brick with respect to the engaging means. This application is a continuation in part of my application Serial No. 401,717, filed August 6, 1920, and on which Letters Patent N o. 1,459,801 were granted June 26, 1923.

Variations within the spirit and scope of my invention are equally comprehended by the foregoing disclosure.

I claim 1. The combination, in an. electric furnace, of .a furnace wall whose inner surface is formed in undulations, comprising alternate, parallel depressions and protuberances, a return-bend resistor element whose straight lengths are adapted to lie within the depressions, adjacent lengths being insulated by intervening protuberances, the resistor lengths directing their heat ra s both forwardly, and against the sides o the depressions, for reflection therefrom, and means for retaining the resistor element in its effective position.

2. The combination, in an electric furnace, of a furnace. wall whose inner surface is formed in undulations, comprising alternate, parallel depressions and protuberances, rail heads extended from the walls and lying at opposite ends of the undulations, at right angles thereto, a return-bend resistor element whose straight lengths are adapted tp lie within the depressions. adjacent lengths being insulated by intervening protuberances, the resistor lengths directing their heat rays both forwardly, and against the sides of the depressions, for reflection therefrom, and the return bends of the resistor element being engaged by the rail heads to thereby retain said resistor element in operative position.

3,. An electric furnace comprising a wall of refractory material, a preformed returnbend resistor element disposed on said wall, and flanged members of refractory material carried by said wall at opposite sides of said element and adapted to engage said element at the return bends thereof to retain the same in position with respect to said Wall, said members' and said element being arranged to permit ready removal and replacement of said element, substantially as specified.

4. An electric furnace comprising a wall having channels formed thereon, a return bend resistor element disposed within said channels, each of said channels having wall portions diverging outwardly and constituting a reflector individual to the portion of said element disposed therein, and flanged members on said wall transversely of and at opposite ends of said channels and adapted to extend over the return bends of said element to retain the same in operative position, substantially as specified.

5. An electric furnace comprising a wall,

having channels thereon, a return bend resistor element disposed in said channels, and refractory members extending over the return bends of said element to retain the same in position relatively to said channels, said members and said element being arranged to permit ready removal and replacenelt of said element, substantially as speci- 6. An electric furnace comprising a support having channels therein and composed of refractory material, a preformed return bend resistor element disposed in said channels, and flanged members of refractory material extending over the return bends of said element for retaining the same in position relatively to said channels, substantially as specified.

7. An electric furnace comprising a wall of refractory material, a preformed return bend resistor element disposed relatively to said wall, means carried by said Wall and interposed between successive strands of said resistor element to maintain said strands in spaced relation, and refractory members carried by said wall and extending over the bends of said element to retain the same in operative position relatively to said wall and to permit ready removal of said element, su sta-ntially as specified.

8. An electric furnace comprising a support of refractory material, a preformed return-bend resistor element disposed on said support, refractory members for retaining sai element in position in close proximity to said sup ort; said refr'actor members being carrie by said support an extending along said element at opposite sides thereof, and refractory portions located between said first named members and interposed between successive strands of lsaid element,

.said members being arranged to permit the ready removal of said element, substantially as specified.

9. An electric furnace comprising a refractory wall enclosing a furnace chamber, s aced refractory members on said wall,

anges on said members of unequal Width and directed towards each other, said members and flanges providing a, recess between the same and an opening communicating with the recess, and a heating unit disposed within said recess and retained in position therein by said flan es, said heating unit having a width less t an that of said recess and greater than that of said opening to permit of the insertion thereof into said recess, substantially as specified.

10. An electric furnace comprising a re* fractory wall inclosing a furnace chamber, s aced refractory members on said wall,

anges on said members of unequal width and directed towards each other, said members and fianges providing a recess between the same and an opening communicating with the recess a. heating unit including a return-bend resistor element retained by said fianges in osition within said recess, lsai-d heating unit having a width less than that of said recess and greater than that of said opening to permit of the insertion thereof into said recess, and means interposed be tween successive strands of said resistor element to maintain said strands in spaced relation, substantiall as specified.

Si ed at Newar in the county of Essex and May 1922.

EDWIN L. SMALLEY.

tate of New Jersey this 25th day of 45 

